Welding with trailing peening stress eliminating method of large nuclear power steel structure

Abstract

The invention discloses a welding with trailing peening stress eliminating method of a large nuclear power steel structure. Multi-layer welding is carried out on the large nuclear power steel structure, when welding is conducted at least from the second layer to the penultimate layer, after one layer is welded, peening is carried out and can make welding seam filling metal completely expand in a hot state, and therefore the residual stress in the cooling shrinkage process is reduced, the bearing capacity of the steel structure is improved, and the welding quality is improved; a pneumatic digger is connected with an air compressor through an air pipe and can extend to each position of the upper air and corners, and the stress eliminating quality is guaranteed; the stress eliminating speed of the pneumatic digger is high, the work of eliminating stress can be finished when welding is finished, and the welding efficiency is improved.

Description

technical field [0001] The invention relates to the new technical field of metal welding technology, in particular to a method for relieving stress by hammering with welding for large steel structures of nuclear power plants. [0002] Background technique [0003] With the continuous development of nuclear power technology, especially the continuous concern of the international community on nuclear safety, the design concept of the third generation nuclear power technology - European Advanced Pressurized Water Reactor EPR has gradually gained popularity. The EPR technology adopts "additive design". On the basis of the original CPR1000, the nuclear safety control function is further increased by increasing the number of active parts and series. [0004] In the EPR technology, the HM-factory is designed with an all-steel structure for the conventional island main workshop. The frame combining concrete structure and steel structure is changed to an all-steel structure frame. ...

AI Technical Summary

Problems solved by technology

In the welding process of large-scale steel structures, the residual stress in the weld will lead to poor bearing capacity of the steel structure, easily lead to quality incidents, and affect the service of the steel structure

In order to release the residual stress in the weld, the existing technology adopts heat treatment method, vibration aging method or ultrasonic impact method to eliminate the residual stress of the weldment. For problems such as long processing time, it can have a better effect on small weldments. For thick plate welds that require multi-layer and multi-pass welding, it is difficult to eliminate residual stress; especially in large steel such as conventional islands. In the case of structural installation and welding, the working surface at high altitude is narrow, the bulky and heavy equipment cannot reach the working surface at high altitude, and the long-term multi-process stress relief process is likely to cause safety accidents, etc., all of which lead to the time-consuming and laborious elimination of residual stress in the existing technology , There are many safety hazards, and the effect of stress relief is not obvious

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